Various technologies have been developed for applying thin films over substrates, and particularly for applying thin films during fabrication of devices of integrated circuitry. Such technologies include chemical vapor deposition (CVD) and atomic layer deposition (ALD). Both ALD and CVD use volatile precursor materials to form a desired material onto a substrate. CVD and ALD differ from one another, however, in that CVD includes reaction of precursors in vapor or plasma phase over a substrate which then forms a deposit onto the substrate. ALD, on the other hand, comprises chemisorption of a precursor component onto a substrate followed by a reaction involving the chemisorbed component to form a desired deposit onto the substrate.
ALD has been used to deposit dielectrics for capacitors, for example oxides such as aluminum oxide, hafnium oxide, and zirconium oxide. In some instances, such oxides are deposited to include multiple different metals and/or metalloids, for example HfxAlyOz, ZrxAlyOz, and ZrxSiyOz. The majority metal component of such materials often provides the desired predominant property of the film, for example Hf or Zr for high dielectric constant. The minority metal component may be provided to offset an undesired characteristic contributed by the majority metal component, for example providing Al or Si to reduce leakage current. Accordingly, it is desirable to be able to carefully control the respective quantity of each respective metal/metalloid in a multiple metal/metalloid dielectric.